drivers/slimbus/core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2011-2017, The Linux Foundation
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/errno.h>
   8 #include <linux/slab.h>
   9 #include <linux/init.h>
  10 #include <linux/idr.h>
  11 #include <linux/of.h>
  12 #include <linux/of_device.h>
  13 #include <linux/pm_runtime.h>
  14 #include <linux/slimbus.h>
  15 #include "slimbus.h"
  16
  17 static DEFINE_IDA(ctrl_ida);
  18
  19 static const struct slim_device_id *slim_match(const struct slim_device_id *id,
  20                                                const struct slim_device *sbdev)
  21 {
  22         while (id->manf_id != 0 || id->prod_code != 0) {
  23                 if (id->manf_id == sbdev->e_addr.manf_id &&
  24                     id->prod_code == sbdev->e_addr.prod_code &&
  25                     id->dev_index == sbdev->e_addr.dev_index &&
  26                     id->instance == sbdev->e_addr.instance)
  27                         return id;
  28                 id++;
  29         }
  30         return NULL;
  31 }
  32
  33 static int slim_device_match(struct device *dev, struct device_driver *drv)
  34 {
  35         struct slim_device *sbdev = to_slim_device(dev);
  36         struct slim_driver *sbdrv = to_slim_driver(drv);
  37
  38         /* Attempt an OF style match first */
  39         if (of_driver_match_device(dev, drv))
  40                 return 1;
  41
  42         return !!slim_match(sbdrv->id_table, sbdev);
  43 }
  44
  45 static void slim_device_update_status(struct slim_device *sbdev,
  46                                       enum slim_device_status status)
  47 {
  48         struct slim_driver *sbdrv;
  49
  50         if (sbdev->status == status)
  51                 return;
  52
  53         sbdev->status = status;
  54         if (!sbdev->dev.driver)
  55                 return;
  56
  57         sbdrv = to_slim_driver(sbdev->dev.driver);
  58         if (sbdrv->device_status)
  59                 sbdrv->device_status(sbdev, sbdev->status);
  60 }
  61
  62 static int slim_device_probe(struct device *dev)
  63 {
  64         struct slim_device      *sbdev = to_slim_device(dev);
  65         struct slim_driver      *sbdrv = to_slim_driver(dev->driver);
  66         int ret;
  67
  68         ret = sbdrv->probe(sbdev);
  69         if (ret)
  70                 return ret;
  71
  72         /* try getting the logical address after probe */
  73         ret = slim_get_logical_addr(sbdev);
  74         if (!ret) {
  75                 slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
  76         } else {
  77                 dev_err(&sbdev->dev, "Failed to get logical address\n");
  78                 ret = -EPROBE_DEFER;
  79         }
  80
  81         return ret;
  82 }
  83
  84 static int slim_device_remove(struct device *dev)
  85 {
  86         struct slim_device *sbdev = to_slim_device(dev);
  87         struct slim_driver *sbdrv;
  88
  89         if (dev->driver) {
  90                 sbdrv = to_slim_driver(dev->driver);
  91                 if (sbdrv->remove)
  92                         sbdrv->remove(sbdev);
  93         }
  94
  95         return 0;
  96 }
  97
  98 static int slim_device_uevent(struct device *dev, struct kobj_uevent_env *env)
  99 {
 100         struct slim_device *sbdev = to_slim_device(dev);
 101
 102         return add_uevent_var(env, "MODALIAS=slim:%s", dev_name(&sbdev->dev));
 103 }
 104
 105 struct bus_type slimbus_bus = {
 106         .name           = "slimbus",
 107         .match          = slim_device_match,
 108         .probe          = slim_device_probe,
 109         .remove         = slim_device_remove,
 110         .uevent         = slim_device_uevent,
 111 };
 112 EXPORT_SYMBOL_GPL(slimbus_bus);
 113
 114 /*
 115  * __slim_driver_register() - Client driver registration with SLIMbus
 116  *
 117  * @drv:Client driver to be associated with client-device.
 118  * @owner: owning module/driver
 119  *
 120  * This API will register the client driver with the SLIMbus
 121  * It is called from the driver's module-init function.
 122  */
 123 int __slim_driver_register(struct slim_driver *drv, struct module *owner)
 124 {
 125         /* ID table and probe are mandatory */
 126         if (!(drv->driver.of_match_table || drv->id_table) || !drv->probe)
 127                 return -EINVAL;
 128
 129         drv->driver.bus = &slimbus_bus;
 130         drv->driver.owner = owner;
 131
 132         return driver_register(&drv->driver);
 133 }
 134 EXPORT_SYMBOL_GPL(__slim_driver_register);
 135
 136 /*
 137  * slim_driver_unregister() - Undo effect of slim_driver_register
 138  *
 139  * @drv: Client driver to be unregistered
 140  */
 141 void slim_driver_unregister(struct slim_driver *drv)
 142 {
 143         driver_unregister(&drv->driver);
 144 }
 145 EXPORT_SYMBOL_GPL(slim_driver_unregister);
 146
 147 static void slim_dev_release(struct device *dev)
 148 {
 149         struct slim_device *sbdev = to_slim_device(dev);
 150
 151         kfree(sbdev);
 152 }
 153
 154 static int slim_add_device(struct slim_controller *ctrl,
 155                            struct slim_device *sbdev,
 156                            struct device_node *node)
 157 {
 158         sbdev->dev.bus = &slimbus_bus;
 159         sbdev->dev.parent = ctrl->dev;
 160         sbdev->dev.release = slim_dev_release;
 161         sbdev->dev.driver = NULL;
 162         sbdev->ctrl = ctrl;
 163         INIT_LIST_HEAD(&sbdev->stream_list);
 164         spin_lock_init(&sbdev->stream_list_lock);
 165         sbdev->dev.of_node = of_node_get(node);
 166         sbdev->dev.fwnode = of_fwnode_handle(node);
 167
 168         dev_set_name(&sbdev->dev, "%x:%x:%x:%x",
 169                                   sbdev->e_addr.manf_id,
 170                                   sbdev->e_addr.prod_code,
 171                                   sbdev->e_addr.dev_index,
 172                                   sbdev->e_addr.instance);
 173
 174         return device_register(&sbdev->dev);
 175 }
 176
 177 static struct slim_device *slim_alloc_device(struct slim_controller *ctrl,
 178                                              struct slim_eaddr *eaddr,
 179                                              struct device_node *node)
 180 {
 181         struct slim_device *sbdev;
 182         int ret;
 183
 184         sbdev = kzalloc(sizeof(*sbdev), GFP_KERNEL);
 185         if (!sbdev)
 186                 return NULL;
 187
 188         sbdev->e_addr = *eaddr;
 189         ret = slim_add_device(ctrl, sbdev, node);
 190         if (ret) {
 191                 put_device(&sbdev->dev);
 192                 return NULL;
 193         }
 194
 195         return sbdev;
 196 }
 197
 198 static void of_register_slim_devices(struct slim_controller *ctrl)
 199 {
 200         struct device *dev = ctrl->dev;
 201         struct device_node *node;
 202
 203         if (!ctrl->dev->of_node)
 204                 return;
 205
 206         for_each_child_of_node(ctrl->dev->of_node, node) {
 207                 struct slim_device *sbdev;
 208                 struct slim_eaddr e_addr;
 209                 const char *compat = NULL;
 210                 int reg[2], ret;
 211                 int manf_id, prod_code;
 212
 213                 compat = of_get_property(node, "compatible", NULL);
 214                 if (!compat)
 215                         continue;
 216
 217                 ret = sscanf(compat, "slim%x,%x", &manf_id, &prod_code);
 218                 if (ret != 2) {
 219                         dev_err(dev, "Manf ID & Product code not found %s\n",
 220                                 compat);
 221                         continue;
 222                 }
 223
 224                 ret = of_property_read_u32_array(node, "reg", reg, 2);
 225                 if (ret) {
 226                         dev_err(dev, "Device and Instance id not found:%d\n",
 227                                 ret);
 228                         continue;
 229                 }
 230
 231                 e_addr.dev_index = reg[0];
 232                 e_addr.instance = reg[1];
 233                 e_addr.manf_id = manf_id;
 234                 e_addr.prod_code = prod_code;
 235
 236                 sbdev = slim_alloc_device(ctrl, &e_addr, node);
 237                 if (!sbdev)
 238                         continue;
 239         }
 240 }
 241
 242 /*
 243  * slim_register_controller() - Controller bring-up and registration.
 244  *
 245  * @ctrl: Controller to be registered.
 246  *
 247  * A controller is registered with the framework using this API.
 248  * If devices on a controller were registered before controller,
 249  * this will make sure that they get probed when controller is up
 250  */
 251 int slim_register_controller(struct slim_controller *ctrl)
 252 {
 253         int id;
 254
 255         id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
 256         if (id < 0)
 257                 return id;
 258
 259         ctrl->id = id;
 260
 261         if (!ctrl->min_cg)
 262                 ctrl->min_cg = SLIM_MIN_CLK_GEAR;
 263         if (!ctrl->max_cg)
 264                 ctrl->max_cg = SLIM_MAX_CLK_GEAR;
 265
 266         ida_init(&ctrl->laddr_ida);
 267         idr_init(&ctrl->tid_idr);
 268         mutex_init(&ctrl->lock);
 269         mutex_init(&ctrl->sched.m_reconf);
 270         init_completion(&ctrl->sched.pause_comp);
 271         spin_lock_init(&ctrl->txn_lock);
 272
 273         dev_dbg(ctrl->dev, "Bus [%s] registered:dev:%p\n",
 274                 ctrl->name, ctrl->dev);
 275
 276         of_register_slim_devices(ctrl);
 277
 278         return 0;
 279 }
 280 EXPORT_SYMBOL_GPL(slim_register_controller);
 281
 282 /* slim_remove_device: Remove the effect of slim_add_device() */
 283 static void slim_remove_device(struct slim_device *sbdev)
 284 {
 285         of_node_put(sbdev->dev.of_node);
 286         device_unregister(&sbdev->dev);
 287 }
 288
 289 static int slim_ctrl_remove_device(struct device *dev, void *null)
 290 {
 291         slim_remove_device(to_slim_device(dev));
 292         return 0;
 293 }
 294
 295 /**
 296  * slim_unregister_controller() - Controller tear-down.
 297  *
 298  * @ctrl: Controller to tear-down.
 299  */
 300 int slim_unregister_controller(struct slim_controller *ctrl)
 301 {
 302         /* Remove all clients */
 303         device_for_each_child(ctrl->dev, NULL, slim_ctrl_remove_device);
 304         ida_simple_remove(&ctrl_ida, ctrl->id);
 305
 306         return 0;
 307 }
 308 EXPORT_SYMBOL_GPL(slim_unregister_controller);
 309
 310 /**
 311  * slim_report_absent() - Controller calls this function when a device
 312  *      reports absent, OR when the device cannot be communicated with
 313  *
 314  * @sbdev: Device that cannot be reached, or sent report absent
 315  */
 316 void slim_report_absent(struct slim_device *sbdev)
 317 {
 318         struct slim_controller *ctrl = sbdev->ctrl;
 319
 320         if (!ctrl)
 321                 return;
 322
 323         /* invalidate logical addresses */
 324         mutex_lock(&ctrl->lock);
 325         sbdev->is_laddr_valid = false;
 326         mutex_unlock(&ctrl->lock);
 327         if (!ctrl->get_laddr)
 328                 ida_simple_remove(&ctrl->laddr_ida, sbdev->laddr);
 329         slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_DOWN);
 330 }
 331 EXPORT_SYMBOL_GPL(slim_report_absent);
 332
 333 static bool slim_eaddr_equal(struct slim_eaddr *a, struct slim_eaddr *b)
 334 {
 335         return (a->manf_id == b->manf_id &&
 336                 a->prod_code == b->prod_code &&
 337                 a->dev_index == b->dev_index &&
 338                 a->instance == b->instance);
 339 }
 340
 341 static int slim_match_dev(struct device *dev, void *data)
 342 {
 343         struct slim_eaddr *e_addr = data;
 344         struct slim_device *sbdev = to_slim_device(dev);
 345
 346         return slim_eaddr_equal(&sbdev->e_addr, e_addr);
 347 }
 348
 349 static struct slim_device *find_slim_device(struct slim_controller *ctrl,
 350                                             struct slim_eaddr *eaddr)
 351 {
 352         struct slim_device *sbdev;
 353         struct device *dev;
 354
 355         dev = device_find_child(ctrl->dev, eaddr, slim_match_dev);
 356         if (dev) {
 357                 sbdev = to_slim_device(dev);
 358                 return sbdev;
 359         }
 360
 361         return NULL;
 362 }
 363
 364 /**
 365  * slim_get_device() - get handle to a device.
 366  *
 367  * @ctrl: Controller on which this device will be added/queried
 368  * @e_addr: Enumeration address of the device to be queried
 369  *
 370  * Return: pointer to a device if it has already reported. Creates a new
 371  * device and returns pointer to it if the device has not yet enumerated.
 372  */
 373 struct slim_device *slim_get_device(struct slim_controller *ctrl,
 374                                     struct slim_eaddr *e_addr)
 375 {
 376         struct slim_device *sbdev;
 377
 378         sbdev = find_slim_device(ctrl, e_addr);
 379         if (!sbdev) {
 380                 sbdev = slim_alloc_device(ctrl, e_addr, NULL);
 381                 if (!sbdev)
 382                         return ERR_PTR(-ENOMEM);
 383         }
 384
 385         return sbdev;
 386 }
 387 EXPORT_SYMBOL_GPL(slim_get_device);
 388
 389 static int of_slim_match_dev(struct device *dev, void *data)
 390 {
 391         struct device_node *np = data;
 392         struct slim_device *sbdev = to_slim_device(dev);
 393
 394         return (sbdev->dev.of_node == np);
 395 }
 396
 397 static struct slim_device *of_find_slim_device(struct slim_controller *ctrl,
 398                                                struct device_node *np)
 399 {
 400         struct slim_device *sbdev;
 401         struct device *dev;
 402
 403         dev = device_find_child(ctrl->dev, np, of_slim_match_dev);
 404         if (dev) {
 405                 sbdev = to_slim_device(dev);
 406                 return sbdev;
 407         }
 408
 409         return NULL;
 410 }
 411
 412 /**
 413  * of_slim_get_device() - get handle to a device using dt node.
 414  *
 415  * @ctrl: Controller on which this device will be added/queried
 416  * @np: node pointer to device
 417  *
 418  * Return: pointer to a device if it has already reported. Creates a new
 419  * device and returns pointer to it if the device has not yet enumerated.
 420  */
 421 struct slim_device *of_slim_get_device(struct slim_controller *ctrl,
 422                                        struct device_node *np)
 423 {
 424         return of_find_slim_device(ctrl, np);
 425 }
 426 EXPORT_SYMBOL_GPL(of_slim_get_device);
 427
 428 static int slim_device_alloc_laddr(struct slim_device *sbdev,
 429                                    bool report_present)
 430 {
 431         struct slim_controller *ctrl = sbdev->ctrl;
 432         u8 laddr;
 433         int ret;
 434
 435         mutex_lock(&ctrl->lock);
 436         if (ctrl->get_laddr) {
 437                 ret = ctrl->get_laddr(ctrl, &sbdev->e_addr, &laddr);
 438                 if (ret < 0)
 439                         goto err;
 440         } else if (report_present) {
 441                 ret = ida_simple_get(&ctrl->laddr_ida,
 442                                      0, SLIM_LA_MANAGER - 1, GFP_KERNEL);
 443                 if (ret < 0)
 444                         goto err;
 445
 446                 laddr = ret;
 447         } else {
 448                 ret = -EINVAL;
 449                 goto err;
 450         }
 451
 452         if (ctrl->set_laddr) {
 453                 ret = ctrl->set_laddr(ctrl, &sbdev->e_addr, laddr);
 454                 if (ret) {
 455                         ret = -EINVAL;
 456                         goto err;
 457                 }
 458         }
 459
 460         sbdev->laddr = laddr;
 461         sbdev->is_laddr_valid = true;
 462         mutex_unlock(&ctrl->lock);
 463
 464         slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
 465
 466         dev_dbg(ctrl->dev, "setting slimbus l-addr:%x, ea:%x,%x,%x,%x\n",
 467                 laddr, sbdev->e_addr.manf_id, sbdev->e_addr.prod_code,
 468                 sbdev->e_addr.dev_index, sbdev->e_addr.instance);
 469
 470         return 0;
 471
 472 err:
 473         mutex_unlock(&ctrl->lock);
 474         return ret;
 475
 476 }
 477
 478 /**
 479  * slim_device_report_present() - Report enumerated device.
 480  *
 481  * @ctrl: Controller with which device is enumerated.
 482  * @e_addr: Enumeration address of the device.
 483  * @laddr: Return logical address (if valid flag is false)
 484  *
 485  * Called by controller in response to REPORT_PRESENT. Framework will assign
 486  * a logical address to this enumeration address.
 487  * Function returns -EXFULL to indicate that all logical addresses are already
 488  * taken.
 489  */
 490 int slim_device_report_present(struct slim_controller *ctrl,
 491                                struct slim_eaddr *e_addr, u8 *laddr)
 492 {
 493         struct slim_device *sbdev;
 494         int ret;
 495
 496         ret = pm_runtime_get_sync(ctrl->dev);
 497
 498         if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) {
 499                 dev_err(ctrl->dev, "slim ctrl not active,state:%d, ret:%d\n",
 500                                     ctrl->sched.clk_state, ret);
 501                 goto slimbus_not_active;
 502         }
 503
 504         sbdev = slim_get_device(ctrl, e_addr);
 505         if (IS_ERR(sbdev))
 506                 return -ENODEV;
 507
 508         if (sbdev->is_laddr_valid) {
 509                 *laddr = sbdev->laddr;
 510                 return 0;
 511         }
 512
 513         ret = slim_device_alloc_laddr(sbdev, true);
 514
 515 slimbus_not_active:
 516         pm_runtime_mark_last_busy(ctrl->dev);
 517         pm_runtime_put_autosuspend(ctrl->dev);
 518         return ret;
 519 }
 520 EXPORT_SYMBOL_GPL(slim_device_report_present);
 521
 522 /**
 523  * slim_get_logical_addr() - get/allocate logical address of a SLIMbus device.
 524  *
 525  * @sbdev: client handle requesting the address.
 526  *
 527  * Return: zero if a logical address is valid or a new logical address
 528  * has been assigned. error code in case of error.
 529  */
 530 int slim_get_logical_addr(struct slim_device *sbdev)
 531 {
 532         if (!sbdev->is_laddr_valid)
 533                 return slim_device_alloc_laddr(sbdev, false);
 534
 535         return 0;
 536 }
 537 EXPORT_SYMBOL_GPL(slim_get_logical_addr);
 538
 539 static void __exit slimbus_exit(void)
 540 {
 541         bus_unregister(&slimbus_bus);
 542 }
 543 module_exit(slimbus_exit);
 544
 545 static int __init slimbus_init(void)
 546 {
 547         return bus_register(&slimbus_bus);
 548 }
 549 postcore_initcall(slimbus_init);
 550
 551 MODULE_LICENSE("GPL v2");
 552 MODULE_DESCRIPTION("SLIMbus core");